Xuchang, in eastern China, is renowned for its geothermal hot springs, which generate a misty steam conferring a soft focus to their surroundings. Department of Architecture Co. principal Amata Luphaiboon built upon that phenomenon for the city’s aptly named Mist Hot Spring Hotel. A complex of four buildings totaling 400,000 square feet, the public spaces are unified by a series of glass installations suggesting light and water.